Selectively locking device

ABSTRACT

A locking element comprising a frame defining a central lumen through which a portion of the elongate member fits; one or more levers extending in the second direction from the frame able to be moved between a locking position and a releasing position; and one or more tabs extending in the first direction from the frame able to be moved by the one or more levers between a locked position and a released position; wherein when the locking element is disposed on an enabling elongate member in a second direction from a second cross section, the one or more tabs prevent the locking element from moving in a first direction beyond a first cross section when disposed in the locked position and do not prevent the locking element from moving in the first direction when disposed in the released position.

FIELD OF THE INVENTION

[0001] The present invention generally pertains to apparatus and methodsfor deploying and retrieving a medical device from an elongate member.More particularly, the present invention generally pertains to apparatusand methods useful for locking a medical device on an elongate memberand subsequently releasing the medical device.

SUMMARY OF THE INVENTION

[0002] Embodiments of the invention pertain to a selectively lockingelement that may be attached to a medical device such as a filter ortherapeutic deliver device and may be disposed on an elongate membersuch as a guidewire. The selectively locking element enables the medicaldevice to be disposed on the elongate member such that it will stay onthe elongate member past a transition region. The elongate member shouldbe configured to enable the selectively locking element to lock. Thismay be done by providing a first region of the elongate member that hasa distance to the central longitudinal axis that is less than thedistance to the central longitudinal axis of a proximal region in adirection along the central longitudinal axis. A guidewire having araised region on it would be an example of an elongate member thatenables the selectively locking element. The selectively locking elementmay comprise one or more tabs and corresponding levers, where the tabshave a locked position and a released position and the levers have acorresponding locking position and releasing position. The tabs may bebiased to the locked position. When the selectively locking element ismoved in a first longitudinal direction over the first region, the tabsmay move into the locked position, preventing moving of the selectivelylocking element back in the second longitudinal direction. A catheter orother object may be used to move the levers to the releasing position,thereby moving the tabs to the released position and allowing movementof the selectively locking element in the second direction. Variouscentering elements may be used. For example, centering arms may beattached to the levers, such that when the levers are moved to thereleasing position, the centering arms position the selectively lockingelement centrally about the elongate member. A centering frame mayextend from the selectively locking element in the second direction overa region of the guidewire in a second direction from the first regionand thereby keep the locking element centered with respect to theelongate member. The elongate member may also include an anti-rotationfeatures, which may be used to orient the selectively locking elementremotely. These anti-rotation features may include one or more flatregions on the elongate member, or one or more longitudinal grooves orridges. Radial or longitudinal radiopaque markings may be used. Theseembodiments, variations thereon, and other embodiments, together withadvantages thereof, will be discussed at length below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0003]FIG. 1 is an orthographic view of an embodiment in accordance withthe invention;

[0004]FIG. 2 is an orthographic view of the embodiment of FIG. 1 on anelongate member in accordance with the invention;

[0005]FIG. 3 is an orthographic view of the embodiment of FIG. 1 on adifferent portion of the elongate member of FIG. 2 in accordance withthe invention;

[0006]FIG. 4 is an orthographic view of the embodiment of FIG. 1 on theportion of the elongate member of FIG. 3 partially disposed in acatheter in accordance with the invention;

[0007]FIG. 5 is an orthographic view of the embodiment of FIG. 1attached to a filter in accordance with the invention;

[0008]FIG. 6 is an orthographic view of an embodiment disposed on anelongate member in accordance with the invention;

[0009]FIG. 7 is an orthographic view of an embodiment of the inventiondisposed on an elongate member in accordance with the invention;

[0010]FIG. 8 is an orthographic view of an embodiment of the inventiondisposed on an elongate member in accordance with the invention; and

[0011]FIG. 9 is an orthographic view of an embodiment of the inventiondisposed on an elongate member in accordance with the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0012] The following detailed description should be read with referenceto the drawings in which like elements in different drawings are numberin like fashion. The drawings, which are not necessarily to scale,depict selected embodiments and are not intended to limit the scope ofthe invention. Those skilled in the art will recognize that many of theexamples provided have suitable alternatives that may be utilized.

[0013]FIG. 1 is an orthographic view of a locking element 100 attachedto a medical device 108 in accordance with the present invention. Aswill be readily appreciated from further description, medical device 108may be any suitable medical device such as a filter or therapeuticdelivery device. Locking element 100 includes tabs 102, which movebetween a locked position and a released position. In this figure, tabs102 are shown in a locked position and in this embodiment, tabs 102 arebiased to be in a locked position. Locking element 100 also includeslevers 104, which move between a locking position and a releasedposition. In this figure, levers 104 are shown in a locking position andin this embodiment, levers 104 are biased to be in a locking position.Tabs 102 and levers 104 are disposed on frame 106, through which a lumen110 is disposed. The free ends of tabs 102 are in a first direction fromthe fixed ends of tabs 102. Likewise, the fixed ends of tabs 102 are ina second direction from the free ends of tabs 102. These referencedirections will remain constant throughout the several embodimentsdescribed. Centering arms 112 may be attached to the second directionends of levers 104. While medical device 108 is attached to lockingelement 100 through struts 114 extending in a second direction fromframe 106, it may be readily appreciated that medical device 108 may beattached through other means such as to levers 104 or centering arms112.

[0014] The number and configuration of tabs 102 and levers 104 is, ofcourse, not limited to that depicted in FIG. 1. While three tabs 102 andthree levers 104 are depicted, embodiments employing as few as one tab102 or one lever 104 have been contemplated. Likewise, embodimentsemploying more tabs 102 or levers 104 have been contemplated and thenumber of tabs or levers used is limited only by the engineeringconsiderations of the particular embodiment. Similarly, although tabs102 and levers 104 are shown in FIG. 1 to be in longitudinal alignment,embodiments have been contemplated where tabs 102 and levers 104 are notin alignment. Alignment of tabs 102 and levers 104 is not essential tothe invention. As an example, the tabs and levers will, of course, notbe in longitudinal alignment when the number of tabs and levers differs.The tabs and levers will be connected to each other such that moving oneor more levers from the locking to the releasing position moves one ormore tabs from the locked to the released position. In the embodimentshown, tabs 102, levers 104 and frame 106 form a monolith unit. Whenlevers 104 are moved from the locking position to the releasingposition, a force is transmitted through the frame to tabs 102 to movethe tabs to the released position. Other means of connecting the leversand the tabs are contemplated, however. One such means is connecting thelevers to the rods using gears or hinges. Another means is making alever and a tab monolithic and pivotably attaching it to the frame usinga spring to provide bias towards the locking position.

[0015] Locking element 100 may include elements such as radiopaque bandsor longitudinal strips to ease radial and longitudinal position of thedevice.

[0016] Turning to FIG. 2, one can see locking element 100 disposed onelongate member 216. Elongate member 216 has portion 218 in the firstdirection and portion 220 in the second direction. The transitionbetween portion 218 and portion 220 is shown as a smooth transition withno sharp edges. The transition need not have this characteristic. Amongother examples of suitable transitions, the transition may be a stepwisetransition or be a simple frustoconical section, for example. Elongatemember 216 is shown as having a circular cross section of uniform shape,but locking element 100 is not limited to being used with elongatemembers having this characteristic. Elongate member 216 may have anycross sectional shape where a portion of the elongate member in thefirst direction fits through frame 10. The cross sectional shape may,for example, be rectangular, triangular, or even irregular. Nor does across section at portion 220 need to be smaller than a cross section atportion 210. Portion 220 may have a longer perimeter or a larger crosssectional area than portion 218. What is important is that there is asurface region on portion 220 where the distance from the region to thecentral longitudinal axis of elongate member 216 is less than thedistance from a surface region of portion 218 to the longitudinal axis.Thus, for example, an elongate member of generally uniform and circularcross section would suffice if there were a channel in the elongatemember in portion 220. Likewise, an elongate member whose portion 220was flattened and thereby had a reduced cross sectional thickness but anincreased cross sectional width would also suffice. An elongate memberof generally constant cross section that has a small region of increasedor decreased cross sectional area may work as well.

[0017] Locking element 100 is disposed on portion 218 of elongate member216. At this portion, tabs 102 are displaced outward by elongate member216, allowing locking element move freely in the first and seconddirections.

[0018] Turning now to FIG. 3, locking element 100 is disposed on portion220 of elongate member 216. Tabs 102 are in a locked position,preventing locking element 100 from being moved in the first directiononto portion 218.

[0019] Turning now to FIG. 4, locking element 100 is disposed on portion220 of elongate member 216. A catheter 222 is moved on locking element100 in a second direction. Catheter 222 is sized to move levers 104 froma locking position to a releasing position. When levers 104 are in thereleasing position, tabs 102 are moved to the released position andlocking element 100 may be moved freely in the first or seconddirection. Of course, locking element 100 need not be operated using acatheter and other means of moving levers 104 are contemplated. Forexample, levers 104 could be operated manually or they could be wrappedin a band which shrinks after a period of time or a change oftemperature. When levers 104 are in the releasing position, the freeends of centering arms 112 abut against elongate member 216 andgenerally center locking element 100 with respect to elongate member216. This may ease the removal of locking element 100.

[0020]FIG. 5 is an orthographic view illustrating one use for a lockingelement 500, substantially similar to locking element 100. Lockingelement 500 is attached with struts 514 to filter 524, allowing thefilter to be selectively locked on a guidewire, for example.

[0021]FIG. 6 is an orthographic view illustrating a locking element 600according to the invention. Locking element 600 has two limbs 624, eachof which has a tab 602 and a lever 604. Levers 604 move between alocking and a releasing position and thereby move tabs 602 between alocked position and a released position. Tabs 602 may be biased to thelocked position. Limbs 624 are connected to frame 606 from which mayextend in a first and a second direction struts 614. Tubes 608 ormedical devices may be attached to the struts. Locking element 600 maybe disposed on elongate member 616 which has a portion in the firstdirection 618 and a portion in the second direction 620. Portion 620 hasa surface region which is closer to the longitudinal axis than a surfaceregion of portion 618. When locking element 600 is on portion 620 ofelongate member 616 and tabs 602 are in the locked position, the lockingelement will be prevented from moving in the first direction ontoportion 618. The tube 608 in the first direction from locking element600 may have a centering function. When locking element 600 is on theportion 620 and tabs 602 are in the locked position, the tube may stayon portion 618 and thereby keep the locking element centered withrespect to the elongate member.

[0022]FIG. 7 is an orthographic view illustrating a locking element 700in accordance with the invention. Locking element 700 has a tab 702attached to a lever 704. It is of course contemplated that theembodiment of FIG. 7 may have more than one set of tabs and levers.Lever 704 moves between a locking and a releasing position and therebymoves tab 702 between a locked position and a released position. Lever704 is attached to frame 706. Extending in a second direction from frame706 are struts 714, which may be connected to a medical device such as afilter or therapeutic deliver system. Locking element 700 is disposed onan elongate member 716. Elongate member has portion 718 and portion 720.Portion 720 contains a surface region where the distance from thatsurface region to a central longitudinal axis is less than the distancefrom a surface region of portion 718 to the central longitudinal axis.Portion 720 also has ridges 726 disposed on either side of this surfaceregion. Tab 702 is adapted to fit within these ridges when it is in thelocked position, thereby preventing rotation of the locking element withrespect to the elongate member. This feature may be useful to orient thelocking member and attached medical device remotely. Locking element 700also includes a longitudinal radiopaque stripe 730. This radiopaquestripe may be used to determine the position of the locking element.

[0023]FIG. 8 is an orthographic view illustrating a locking element 800disposed on an elongate member 816 in accordance with the invention.Locking element 800 includes tabs 802, which may move between a lockedposition and a released position, and levers 804, which may move betweena locking position and a releasing position. Tabs 802 and levers 804 areattached to a frame 806. Struts may extend in both directions from thisframe, attached to medical or other devices. Centering elements 812 maybe attached to the levers 804. When levers 804 are moved to thereleasing position, tabs 802 are moved to the released position, therebyallowing locking device 800 to move over portion 818 of elongate member816.

[0024]FIG. 9 is an orthographic view illustrating a locking element 900disposed on an elongate member 916 in accordance with the invention.Locking element 900 has a tab 902 attached to a lever 904. It is ofcourse contemplated that the embodiment of FIG. 9 may have more than oneset of tabs and levers. Lever 904 moves between a locking and areleasing position and thereby moves tab 902 between a locked positionand a released position. Tab 902 and lever 904 are attached to a frame906. Struts may extend in a second direction from frame 906, which maybe connected to a medical device such as a filter or therapeutic deliversystem. Locking element 900 is disposed on an elongate member 916.Elongate member has portion 918 and portion 920. Portion 920 contains asurface region where the distance from that surface region to a centrallongitudinal axis is less than the distance from a surface region ofportion 918 to the central longitudinal axis. Portion 920 also hasgroove 928 disposed on portion 920. Tab 902 is adapted to fit in groove928 when it is in the locked position, thereby preventing rotation ofthe locking element with respect to the elongate member. This featuremay be useful to orient the locking member and attached medical deviceremotely.

[0025] In use, the locking element may be attached to a filter,therapeutic delivery device, or other medical device. The lockingelement may be slid in a distal direction over an elongate member. Theelongate member will have a second portion in the second direction witha surface region that is closer to the central longitudinal axis of theelongate member than a surface region of a first portion of the elongatemember. When the locking element is over the second portion, one or moretabs will move into the locked position, preventing movement in thefirst direction. To then allow the locking device to move in the firstdirection, the levers may be moved from the locking position to thereleasing position thereby moving the tabs from the locked position tothe released position. When the tabs are in the released position, thelocking element may then be moved in the first direction.

[0026] As an illustrative example, suppose the selectively lockingfilter apparatus of FIG. 5 is put on a guidewire having astepwise-reduced diameter, where the smaller diameter is distal thelarger diameter, inserted percutaneously into a patient. The filterapparatus may be put into a catheter to reduce the diameter of thefilter and advanced distally into the patient. When the filter apparatusis on the larger diameter portion of the guidewire, the tabs will beforced to a released position by the guidewire. When the filterapparatus passes the stepwise transition, the tabs will fall into thelocked position and the catheter may be withdrawn. A catheter may thenbe introduced over the filter apparatus again, moving the levers to thereleasing position and allowing the filter to be moved proximally offthe guidewire.

[0027] The locking element may be made from any number of biocompatiblematerials. If the locking element is unitary, a combination offlexibility where the material bends at the frame and rigidity in thetabs and levers may be desirable. Merely as examples and not as anexhaustive list, such material may include metals such as stainlesssteel or Nitinol or may include plastics like nylon orpolyvinylchloride. The material may be formed into the locking elementor parts of the locking element by laser cutting, molding, welding,brazing or other process well known in the art.

[0028] It will be understood that this disclosure, in many respects, isonly illustrative. Changes may be made in details, particularly inmatters of shape, size, material, and arrangement of parts withoutexceeding the scope of the invention. Those skilled in the art willrecognize that the present invention may be manifested in a variety offorms other than the specific embodiments described and contemplatedherein. Accordingly, departures in form and detail may be made withoutdeparting from the scope and spirit of the present invention asdescribed in the appended claims.

What is claimed is:
 1. A locking element for locking a medical device toan elongate member having a central longitudinal axis and a first crosssection having a first perimeter and a second cross section having asecond perimeter where a portion of the second perimeter is closer tothe central longitudinal axis than a portion of the first perimeter, thelocking element comprising: a frame defining a central lumen throughwhich a portion of the elongate member fits; one or more leversextending in the second direction from the frame able to be movedbetween a locking position and a releasing position; and one or moretabs extending in the first direction from the frame able to be moved bythe one or more levers between a locked position and a releasedposition; wherein when the locking element is disposed on the elongatemember in the second direction from the second cross section, the one ormore tabs prevent the locking element from moving in the first directionbeyond the first cross section when disposed in the locked position anddo not prevent the locking element from moving in the first directionwhen disposed in the released position.
 2. The element of claim 1,wherein the locking element is monolithic.
 3. The element of claim 2,wherein when the one or more levers is in the second direction from thesecond cross section, there is a gap between the one or more levers anda portion of the elongate member in a second direction from the secondcross section.
 4. The element of claim 3, wherein the gap between theone or more levers and the elongate member increases in the seconddirection when the one or more levers are in the locked position.
 5. Theelement of claim 1, wherein when the tabs are in the locked position, aportion of the one or more tabs cannot fit outside the first perimeter.6. The element of claim 1, wherein when the locking element is disposedon the elongate member in the second direction from the second crosssection, the levers are closer to the elongate member in the releasingposition than in the locking position and the tabs are closer to theelongate member in the locked position than in the released position. 7.The element of claim 6, wherein moving the levers from the lockingposition to the releasing position causes the tabs to be moved from thelocked position to the released position.
 8. The element of claim 1,wherein the one or more levers and the one or more tabs are equal innumber.
 9. The element of claim 8, wherein each of the one or more tabsextend from the frame at a position opposite one of the tabs.
 10. Theelement of claim 1, wherein the locking element further comprises strutsto connect the locking element to a medical device.
 11. The element ofclaim 10, wherein the struts are attached to the central element. 12.The element of claim 10, wherein struts extend in a second directionfrom the locking element.
 13. The element of claim 12, wherein thestruts are attached to the levers.
 14. The element of claim 1, whereinthe locking element comprises a flexible material.
 15. The element ofclaim 14, wherein the locking element comprises a super-elasticmaterial.
 16. The element of claim 15, wherein the locking elementcomprises a nickel-titanium alloy.
 17. The element of claim 1, whereinthe one or more levers and the one or more tabs are uniformlydistributed around the frame.
 18. The element of claim 1, wherein theone or more tabs comprise two opposing tabs and the one or more leverscomprise two opposing levers.
 19. The element of claim 1, wherein theone or more tabs comprise three equally spaced tabs and the one or morelevers comprise three equally spaced levers.
 20. The element of claim 1,wherein the one or more levers can be actuated by an object moving inthe second direction.
 21. The element of claim 1, wherein the one ormore tabs are biased to the locked position.
 22. The element of claim 1,wherein the one or more levers are biased to the locking position. 23.The element of claim 1, wherein the medical device is a filter.
 24. Theelement of claim 1, wherein the element further comprises one or moreradiopaque bands.
 25. The element of claim 1, wherein the elementfurther comprises one or more radiopaque longitudinal stripes.
 26. Theelement of claim 1, wherein the one or more levers comprise two or morelevers, further comprising two or more centering arms attached to thetwo or more levers such that when the levers are moved to the releasingposition, the two or more centering arms position the elongate membercentrally with respect to the element.
 27. An apparatus for selectivelylocking a medical device, comprising an elongate member having a centrallongitudinal axis and a first cross section having a first perimeter anda second cross section having a second perimeter where a portion of thesecond perimeter is closer to the central longitudinal axis than aportion of the first perimeter and having one or more surfaces in thesecond direction from the first cross section adapted for receiving oneor more tabs; and a locking element having a frame defining a centrallumen through which a portion of the elongate member fits, one or morelevers extending in the second direction from the frame able to be movedbetween a locking position and a releasing position, and one or moretabs extending in the first direction from the frame able to be moved bythe one or more levers between a locked position and a releasedposition; wherein a portion of the elongate member in the seconddirection from the first cross section is adapted for receiving one ormore of the tabs and when the locking element is disposed on theelongate member in the second direction from the second cross section,the one or more tabs prevent the locking element from moving in thefirst direction beyond the first cross section and prevent the lockingdevice from rotating about the elongate member when disposed in thelocked position and do not prevent the locking element from moving inthe first direction when disposed in the released position.
 28. Theapparatus of 27, wherein the elongate member further comprises one ormore longitudinal radiopaque stripes.
 29. The apparatus of 27, whereinthe one or more surfaces are flat.
 30. The apparatus of 27, wherein theone or more surfaces have a central portion and one or more longitudinalridges adjacent thereto.
 31. The apparatus of 30, wherein each centralregion of the one or more surfaces have two longitudinal ridges adjacentthereto.
 32. The apparatus of 27, wherein the one or more surfacesconform to the tabs.
 33. The apparatus of 27, wherein the one or moresurfaces have a central region and one or more longitudinal groovesadjacent thereto.
 34. The apparatus of 27, wherein each central regionof the one or more surfaces have two longitudinal grooves adjacentthereto.
 35. The apparatus of 27, wherein the elongate member has a stopnear the end in the second direction.
 36. A process for releasablylocking a medical device on an elongate member, comprising: providing anelongate member having a central longitudinal axis and a first crosssection having a first perimeter and a second cross section having asecond perimeter where a portion of the second perimeter is closer tothe central longitudinal axis than a portion of the first perimeter;providing a locking element having a frame defining a lumen throughwhich a portion of the elongate member may fit, one or more leversextending from the frame in the second direction able to be actuatedbetween a locking position and a releasing position, and one or moretabs extending in the first direction from the frame able to be actuatedby the one or more levers between a locked position and a releasedposition; and advancing the locking element on the first end of theelongate member in the second direction beyond the first cross section.37. The process of claim 36, wherein when the locking element isadvanced beyond the first cross section, the one or more tabs move tothe locked position.
 38. The process of claim 36, further comprising thesteps of: actuating the levels to the releasing position; and advancingthe locking element in the first direction past the first cross section.39. The process of claim 36, wherein the step of providing an elongatemember further includes providing one or more surfaces on the elongatemember in the second direction from the first cross section adapted toreceive one or more tabs and wherein the step of advancing the lockingelement further includes the step of rotating the locking element sothat one of the tabs aligns with one of the surfaces such that when thetabs are in the locked position, the locking device is prevented fromrotating with respect to the elongate member.
 40. The process of claim39, wherein the step of providing one or more surfaces further includesthe step of providing one or more flat surfaces.
 41. The process ofclaim 39, wherein the step of providing one or more surfaces furtherincludes the step of providing one or more surfaces having a centerportion and one or more longitudinal ridges adjacent the center portion.42. The process of claim 41, wherein the step of providing one or moresurfaces further includes the step of providing center surfaces whichare flat.
 43. The process of claim 41, wherein the step of providing oneor more surfaces further includes the step of providing center surfaceswhich conform to the tabs.
 44. The process of claim 41, wherein the stepof providing one or more surfaces further includes the step of providingtwo adjacent longitudinal ridges.